JP2000087807A - Egr valve device for cylinder injection type engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an EGR valve device for a cylinder injection type engine, which can cool an EGR control valve, and also can enhance relatively an intake filling efficiency, and besides is formed into a compact size. SOLUTION: This EGR valve device comprises an EGR control valve 22 whose valve element 22a is reciprocated and a valve housing 21. An exhaust gas passage 27 and a cooling water passage 28 are formed in the valve housing 21 such that they are extended from one end part of the valve housing 21 to the other end part thereof. Both the passages 27, 28 are so formed that they are overlapped in the opening/closing direction of the valve element 22a by one end part side and other end part side of the valve housing 21. The positions of the passages 27, 28 in the opening/closing direction of the valve element 22a are formed to be opposed to each other by the one end part side and other end part side of the valve housing 21. The exhaust gas passage 27 and cooling water passage 28 cross each other in the EGR control valve mounting part of the valve housing 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EGR valve device for a direct injection type engine, and more particularly to a cooling structure for an EGR valve device.

[0002]

2. Description of the Related Art In a direct injection type engine in which fuel is directly injected into a combustion chamber by an injector, an air-fuel ratio of an air-fuel mixture can be set to a so-called super-lean in order to improve fuel efficiency. When the air-fuel ratio is set to be extremely lean, the combustion temperature becomes higher than that of a general engine, and the NOx in the exhaust gas increases remarkably.
A large amount of exhaust gas is introduced into the intake system by the device, and the combustion temperature is reduced to reduce NOx emissions.

In the EGR device, an exhaust pipe and an intake manifold are connected by an exhaust gas recirculation pipe.
An EGR control valve is interposed in this pipe to open and close the EGR control valve according to the operating state of the engine.

[0004]

However, when a large amount of exhaust gas is introduced into the intake system as described above, the amount of exhaust gas flowing through the EGR control valve increases as compared with a general engine, and the EGR control valve is excessively heated. A problem arises. When the EGR control valve is excessively heated, the contact portion between the valve body and the valve seat is easily worn.

[0005] The EGR control valve is excessively heated because it opens when the engine operating range is in a low / medium load operating range and closes by closing the accelerator, in other words, frequently opens and closes. In this case, the contact portion is significantly worn, and the durability is reduced.

[0006] Further, there is another problem that the temperature of the intake air increases due to an increase in the amount of exhaust gas introduced, and the efficiency of charging the intake air decreases.

In order to solve such a problem, E
It is conceivable to provide a GR control valve or a cooling device for cooling exhaust gas. However, simply providing a cooling device in the EGR valve device increases the size of the EGR valve device.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is possible to cool an EGR control valve and to relatively increase the charging efficiency of intake air. It is an object to provide an EGR valve device for an engine.

[0009]

An EGR valve device for a direct injection type engine according to the present invention comprises an EGR control valve and a valve housing, and an exhaust gas passage and a cooling water passage are provided in the valve housing at one end of the valve housing. The exhaust gas passage and the cooling water passage intersect with each other near the EGR control valve mounting portion of the valve housing.

According to the present invention, since the heat of the valve housing is transmitted by conduction to the cooling water flowing through the cooling water passage, the exhaust gas flowing through the exhaust gas passage of the valve housing,
The EGR control valve mounted on the valve housing can be cooled by the cooling water. Further, since the exhaust gas passage and the cooling water passage intersect at the EGR control valve mounting portion, the cooling water can flow near the EGR control valve, and the EGR control valve can be efficiently cooled.

According to a second aspect of the present invention, there is provided an in-cylinder injection type EGR valve device for an in-cylinder injection type engine according to the above-mentioned invention, wherein the valve body reciprocates the EGR control valve. The exhaust gas passage and the cooling water passage overlap at one end side and the other end side of the valve housing in the opening and closing direction of the valve body, and are positioned at one end side and the other end side with respect to the opening and closing direction of the valve body. Are formed in the opposite manner.

According to the present invention, since the exhaust gas passage is opened and closed by the reciprocating valve body, the exhaust gas passage is located upstream and downstream of the EGR control valve (one end and the other end of the valve housing). Side) is formed so as to be deviated to one side and the other in the opening and closing direction of the valve body. Since the upstream side and the downstream side of the cooling water passage are formed so as to overlap in the opening and closing direction of the valve body with respect to the upstream side and the downstream side of the exhaust gas passage, the valve is provided with respect to the upstream side and the downstream side of the exhaust gas passage. The cooling water passage can be formed by using a dead space formed in one and the other of the opening and closing directions of the body.

According to a third aspect of the present invention, there is provided an EGR valve device for a direct injection type engine according to the first or second aspect of the invention. Is assembled into a single case by assembling a valve body, a valve seat and a valve body driving device, and the EGR control valve is mounted on a valve housing.

According to the present invention, the valve housing is provided with E
Since there is no need to provide a valve seat for the GR control valve, a valve seat support is not required inside the valve housing. For this reason, since there is no restriction caused by providing the valve seat support portion, that is, there is no restriction that the valve body support portion is firmly formed or that the position of the valve seat does not change due to thermal expansion. The degree of freedom in designing the exhaust gas passage and the cooling water passage in the valve housing is increased, and both passages can be formed in ideal shapes.

Further, in the EGR valve device according to the present invention, the shape of the other portion of the valve housing can be freely changed as long as the shape and dimensions of the portion where the EGR control valve is mounted in the valve housing match. .
That is, even if a plurality of types of valve housings are formed in accordance with the model of the engine, only one type of EGR control valve may be used.

According to a fourth aspect of the present invention, there is provided an in-cylinder injection type EGR valve device for an in-cylinder injection engine according to any one of the first to third aspects. The engine is fixed to the outer wall of the engine. The upstream end of the cooling water passage, which is open to the mating surface of the valve housing on the engine side, is connected to the cooling water outlet of the engine. The EGR control valve is formed so as to surround the EGR control valve from at least three sides including the EGR control valve side located on the side opposite to the engine.

According to the present invention, the engine side of the EGR control valve is cooled by conducting heat from the valve housing to the engine, and the side opposite to the engine has a cooling water passage formed so as to surround the engine side. Cooled by flowing cooling water. Further, the cooling water flows directly from the engine into the valve housing without passing through the piping.

According to a fifth aspect of the present invention, there is provided an in-cylinder injection engine EGR valve device according to the fourth aspect of the present invention, wherein the downstream side of the exhaust gas passage is provided in the middle of the intake manifold. The intake manifold is connected to the intake passage via a metal pipe, and the upstream end of the intake manifold is fixed to the valve housing.

According to the present invention, the middle of the intake manifold whose downstream end is supported by the engine and the upstream end are connected to the valve housing. Therefore, the throttle protrudes from the intake manifold upstream, that is, from the engine. The portion where the valve is mounted can be firmly supported by the EGR valve device. This eliminates the need for a stay that exclusively supports the portion where the throttle valve is mounted.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an EGR valve device for a direct injection engine according to the present invention will be described below with reference to FIGS.
This will be described in detail. FIG. 1 is a front view of an in-cylinder injection engine equipped with an EGR valve device according to the present invention, FIG. 2 is a side view showing the engine viewed from an intake manifold side, FIG. 3 is a plan view of the engine, and FIG. FIG. 5 is an exploded perspective view showing the cylinder head and the EGR valve device, FIG. 6 is a sectional view taken along the line VI-VI of the EGR valve device in FIG. 4, and FIG. 7 is FIG. VI in
8 is a sectional view of the EGR valve device as viewed from the downstream side, and FIG. 9 is a sectional view taken along line IX-IX in FIG.

In these figures, what is indicated by reference numeral 1 is a direct injection engine according to this embodiment.
The engine 1 is a water-cooled DOHC type four-cylinder engine for an automobile, and includes a cylinder block 2 and a cylinder head 3.
And a head cover 4 and the like. The engine 1 is mounted on a vehicle body (not shown) such that the horizontal direction in FIG. 1 is substantially horizontal.

As shown in FIG. 1, the cylinder head 3 has an intake manifold 6 mounted on one side thereof via an intake control valve unit 5, and an injector 7 for each cylinder as shown in FIGS. 2 and 5. The exhaust pipe 8 is attached to the other side. Also, this cylinder head 3
As shown in FIGS. 1 and 3, an EG, which will be described later, is provided at one end of the intake camshaft 9 and the exhaust camshaft 10 in the axial direction.
An R valve device 11 and a high-pressure fuel pump 12 are mounted.
As shown in FIG. 3, a power for transmitting the rotation of the crankshaft 13 (see FIG. 1) to the two camshafts 9 and 10 is provided at the other end of the engine 1 in the axial direction of the two camshafts. A transmission device 14 is provided.

The intake control valve unit 5 includes a primary port 14 (FIG. 5) formed in the cylinder head 3 for each cylinder.
) And an intake passage connected to the secondary port 15, and an open / close valve for opening and closing the intake passage connected to the secondary port 15.

The intake manifold 6 includes branch pipes 6a formed for each cylinder and fixed to the intake control valve unit 5, a surge tank 6b connecting the branch pipes 6a, and an intake camshaft 9 from the surge tank 6b. And an intake inflow pipe 6c extending toward the EGR valve device 11 along the axial direction.
A flange 6d for connecting a throttle valve device (not shown) is integrally formed at the upstream end of the intake pipe 6c.

The injector 7 is disposed so as to be located between two intake ports for each of the cylinders, that is, between the primary port 14 and the secondary port 15, and between the two ports and between the bottom of the cylinder head (the cylinder block and the cylinder block). (A mating surface) of the fuel chamber is directly injected into a combustion chamber (not shown). The fuel inlet of each injector 7 is connected to a fuel outlet of the high-pressure fuel pump 12 via a fuel rail indicated by reference numeral 16 in FIG. 5 and a fuel supply pipe 17 connected to one end of the fuel rail 16. .

The high pressure fuel pump 12 is attached to the one end of the cylinder head 3 on the side of the exhaust camshaft 10, and the exhaust camshaft 10 rotates so that plungers (not shown) are provided in the three cylinders 12a. Are reciprocated to pump the fuel supplied from a low-pressure fuel pump (not shown) to the injector 7.

The EGR valve device 11 is interposed in a conventionally known EGR device for introducing exhaust gas into an intake passage.
As shown in FIG. 4 and FIG.
And an EGR control valve 22 attached to the valve housing 21. The valve housing 21 is fixed to the intake camshaft 9 at the one end of the cylinder head 3 via a seal member 23.

It should be noted that E is attached to the one end of the cylinder head 3.
In order to increase the space for disposing the GR valve device 11 and the high-pressure fuel pump 12, the ignition coil attached to the one end of the cylinder head in the conventional engine is directly connected to the ignition plug in the engine 1. Connected. The ignition device of the engine 1
An ignition unit 24 having an ignition coil and a switching element is attached to an ignition plug, and an ignition signal is sent from the ignition timing control device (not shown) to the ignition unit 24.

The EGR valve device 11 is fixed to the cylinder head 3 by using four fixing bolts 25 as shown in FIG. 4 and a bolt fastening portion for improving the accuracy of the fixing position. A knock pin 26 (see FIGS. 6 and 8) is interposed. The knock pin 26 is formed in a cylindrical shape, through which the fixing bolt 25 passes, and fitted to both the valve housing 21 and the cylinder head 3.

As shown in FIG. 1, the valve housing 21 extends from one side connecting the intake manifold 6 of the cylinder head 3 to the other side connecting the exhaust pipe 8 and extends below the high-pressure fuel pump 12. As shown in FIG. 7, an exhaust gas passage 27 and a cooling water passage 28 are formed inside the valve housing 21 so as to extend in the same direction as the extending direction.

The exhaust gas passage 27 is formed so that a concave portion 29 for mounting the EGR control valve 22 is a part thereof. More specifically, the exhaust gas passage 27 includes the concave portion 29 formed to open upward in the valve housing 21, and a first portion formed at the bottom of the concave portion 29.
An upstream portion 27a extending from the communication port 30 to the exhaust camshaft 10 side (the right side in FIG. 7) in the lower portion of the valve housing 21;
The upper portion of the valve housing 21 is formed from a second communication port 31 formed in the peripheral wall of the concave portion 29 and a downstream portion 27b extending in the opposite side to the upstream portion 27a.

The upstream end of the exhaust gas passage 27 opens at the right end of the valve housing 21 in FIG.
As shown in FIG. 1 and FIG. 3, it is connected to the inside of the collecting part 8 a of the exhaust pipe 8 via the exhaust gas introduction pipe 32.

The downstream end of the exhaust gas passage 27 opens at the other end of the valve housing 21, and as shown in FIGS.
The exhaust manifold 33 connects to an intake passage in the intake manifold 6. The exhaust gas outlet pipe 33 is made of a metal pipe, and has an upstream end fixed to the valve housing 21 and a downstream end fixed to a point in the intake manifold 6 c of the intake manifold 6.

The intake inlet pipe 6c has a flange 6d for mounting a throttle valve device at an upstream end thereof fixed to a bracket formed integrally with the valve housing 21. The valve housing 21 is provided with the knock pin 26.
Therefore, the connection with the intake manifold 6 can be performed accurately. As shown in FIG. 2, the intake manifold 6 has a fixing stay 6e provided on the cylinder block 2 and provided on the surge tank 6b and the downstream side of the intake inflow pipe 6c.

The EGR control valve 22 mounted in the recess 29 of the exhaust gas passage 27 has a reference numeral 22a in FIG.
The valve body drive device 22b reciprocates the valve body shown in the vertical direction in the vertical direction, and the valve body 22a, the valve seat 22c and the valve body drive device 22b are assembled into one case 22d to constitute an assembly. ing. The EGR control valve 22 has a lower portion of the case 22d fitted in the concave portion 29 and is fixed to an upper portion of the valve housing 21 by fixing bolts 35 (see FIGS. 2 to 5). The position where the EGR control valve 22 is mounted is, as shown in FIG.
The valve housing 21 is set so as to be located on the intake camshaft 9 side while being fixed to the cylinder head 3.

The case 22d has a bottom wall and a valve seat 22c.
An opening for passing exhaust gas is formed in a portion corresponding to the second communication port 31 on the upper peripheral wall, and a space below the valve element driving device 22b is formed so as to form a part of an exhaust gas passage. ing. That is, as shown in FIG.
The exhaust gas passage is closed by abutment of the valve body 2a on the valve seat 22c, and the exhaust gas passage is opened by separating the valve body 22a downward from the valve seat 22c. Exhaust gas flows between the case 22d and the valve housing 21.
A seal member (not shown) is interposed to prevent leakage through the gap between the groove 29 and the recess 29.

The valve body driving device includes a motor as a power source. When the throttle valve (not shown) of the engine 1 is closed or when the engine operating range is in a high rotation and high load range, the valve body 22a is driven. As shown in FIG. 7, a structure is adopted in which the valve body 22a is moved downward from the fully closed position by moving the valve body 22a to the fully closed position and when the engine operating range is in the low / medium rotation, low / medium load range. The opening of the valve body 22a is increased or decreased in accordance with the engine speed and / or load.

As shown in FIGS. 6 to 9, the cooling water passage 28 has an upstream portion 28a formed above the upstream portion 27a of the exhaust gas passage 27 so as to overlap when viewed from above, and a downstream portion of the exhaust gas passage 27. A downstream portion 28b formed below the portion 27b so as to overlap when viewed from above;
A communication portion 28c formed in the EGR control valve mounting portion for communicating the upstream portion 28a and the downstream portion 28b.
It is composed of

The upstream portion 28a of the cooling water passage 28 has an upstream end opened at a mating surface 21a (see FIG. 6) of the valve housing 21 on the cylinder head 3 side, and the valve housing 21 is fixed to the cylinder head 3. The opening corresponds to the cooling water outlet 36 of the cylinder head 3 (FIG. 5).
Reference). Further, in the upstream portion 28a of the cooling water passage 28, reference numerals 37, 3 in FIG.
A hole for mounting a temperature sensor indicated by 8, a heater hot water outlet 39, and an air vent 40 are connected.

The downstream portion 28b of the cooling water passage 28 is connected to a radiator (not shown) through a pipe (not shown) from a main drain pipe 41 formed integrally with the valve housing 21. In this embodiment, a sub-drain pipe 42 is provided so as to branch from the main drain pipe 41, and a cooling water pump (not shown) supplies cooling water from the sub-drain pipe 42 via a bypass pipe (not shown). The structure leads to the entrance side of.

In the cooling system of the engine 1, cooling water is sucked from a radiator through a thermostat into a cooling water pump, and is sent from the cooling water pump to the cylinder block 2 and the cylinder head 3 under pressure. A configuration is adopted in which the radiator returns through the EGR valve device 11. When the thermostat is closed, the cooling water is guided from the auxiliary drain pipe 42 to the upstream side of the cooling water pump via the bypass pipe without passing through the radiator.

The communication portion 28c of the cooling water passage 28
The recess 29 in which the GR control valve 22 is mounted is formed so as to surround from the side. That is, the communication portion 28c
A first passage 28d adjacent to the concave portion 29 on the side opposite to the cylinder head 3, and a first passage 28d
The cooling water passage 28 is formed so as to extend in the axial direction of the camshaft on the more upstream side and the downstream side.
The second and third passages 28e and 28f are connected to the second passage 8b.

As described above, the exhaust gas passage 27 and the cooling water passage 2
8 are formed in the valve housing 21 so that these two passages overlap each other on one end side and the other end side of the valve housing 21 in the up-down direction (opening / closing direction of the valve body 22a). Valve body 2 with the other end
The position of 2a in the opening and closing direction is reversed. For this reason,
The exhaust gas passage 27 and the cooling water passage 28 can intersect at the EGR control valve mounting portion of the valve housing 21.

That is, the upstream portion 27a of the exhaust gas passage 27
The upstream portion 28a of the cooling water passage 28 is located above the exhaust gas passage 27, the downstream portion 28c of the cooling water passage 28 is located below the downstream portion 27b of the exhaust gas passage 27, and the exhaust gas passage 27 is located at the EGR control valve mounting portion from below. While formed to extend upward, the cooling water passage 28 is formed to extend downward from above at the same portion, and both passages intersect at the EGR control valve mounting portion.

The EGR valve device 11 configured as described above
According to the EGR control valve 22 during engine operation,
, The exhaust gas flows from the exhaust pipe 8 through the exhaust gas introduction pipe 32 into the exhaust gas passage upstream portion 27 a of the valve housing 21. The exhaust gas flows from the upstream portion 27a to the exhaust gas outlet pipe 33 through the EGR control valve 22 and the downstream portion 27b of the exhaust gas passage 27, and is introduced from the exhaust gas outlet pipe 33 into the intake passage in the intake manifold 6. You.

On the other hand, the cooling water of the engine 1 flows from the cooling water outlet 36 of the cylinder head 3 into the cooling water passage 28 in the valve housing 21, and from the upstream portion 28a of the cooling water passage 28 through the communication portion 28c. Flows to the downstream portion 28b,
From this downstream part 28b, it is discharged to a radiator (not shown).

As described above, the cooling water is supplied to the valve housing 21.
The heat of the valve housing 21 is transmitted to the cooling water by conduction by flowing into the inside. Therefore, the exhaust gas flowing through the exhaust gas passage 27 and the EGR control valve 22 attached to the valve housing 21 can be cooled by the cooling water. Further, the exhaust gas passage 27 and the cooling water passage 2
8 intersects with the EGR control valve mounting portion, so that the cooling water can flow near the EGR control valve 22, and the EGR control valve 22 can be efficiently cooled.

Further, the valve element 22 which reciprocates in the vertical direction is provided.
a, the exhaust gas passage 27 is opened and closed.
The upstream portion 27a of the exhaust gas passage 27 is formed to be deviated below the valve body 22a, and the downstream portion 27b of the exhaust gas passage 27 is formed to be deviated above the valve body 22a. This exhaust gas passage 2
Cooling water passage 2 for the upstream portion 27a and the downstream portion 27b of
8 is formed so that the upstream portion 28b and the downstream portion 28b of the exhaust gas passage 27 overlap in the vertical direction.
The cooling water passage 28 can be formed by using a dead space formed above the upper part a and below the downstream part 27b. Therefore, the cooling water passage 28 can be formed while minimizing an increase in the space occupied by the valve housing 21.

EGR valve device 11 according to this embodiment
Is the EGR control valve 22, the valve body 22a, the valve seat 2
2c and the valve body driving device 22b in one case 22d.
And the EGR control valve 22 is attached to the valve housing 21.
There is no need to provide the valve seat 22c of the EGR control valve 22 in the valve housing 21, and no valve seat support portion is required inside the valve housing 21.

In the case where the valve seat 22c is provided in the valve housing 21, the valve seat supporting portion must be formed firmly, that is, thick so as to receive the load applied from the valve body 22a when fully closed. No. In addition, the wall formed around the valve seat support portion must be formed so that the position of the valve seat 22c with respect to the valve body 22a does not significantly change even if thermal expansion occurs in the valve housing 21.

However, by adopting this embodiment, the valve housing 21 does not suffer from the above-mentioned restrictions. As a result, the valve housing 2
The degree of freedom in designing the exhaust gas passage 27 and the cooling water passage 28 in the interior 1 is increased, and both passages can be formed in an ideal shape.

In the EGR valve device 11 according to this embodiment, as long as the shape and dimensions of the concave portion 29 for mounting the EGR control valve 22 in the valve housing 21 match, the shape of other portions of the valve housing 21 is free. Can be changed to That is, even if a plurality of types of valve housings 21 are formed in accordance with the model of the engine, one type of EGR control valve 22 may be used.

Furthermore, the EGR according to this embodiment
The valve device 11 has a structure in which the valve housing 21 is fixed to the outer wall of the cylinder head 3, and an upstream end of the cooling water passage 28 which is opened on the engine side mating surface 21 a of the valve housing 21 is provided with a cooling water outlet of the cylinder head 3. 3
6 and a portion (the communication portion 28 c) corresponding to the EGR control valve 22 in the cooling water passage 28 is connected to the EGR control valve 22 from three directions including the EGR control valve side portion located on the opposite side to the cylinder head 3. The EGR control valve 22
The cylinder head 3 side of the valve housing 21
Can be cooled by conducting heat to the cylinder head, and the side opposite to the cylinder head 3 can be cooled by cooling water flowing through a cooling water passage 28 formed so as to surround the cylinder head 3.

Since the cooling water directly flows from the cylinder head 3 into the valve housing 21, there is no need to provide a pipe for guiding the cooling water to the cooling water passage 28 in the valve housing 21.

In addition, the EGR valve device 11 according to this embodiment is configured such that the downstream portion 27b of the exhaust gas passage 27 in the valve housing 21 is connected to the exhaust passage 33 made of metal in the intake passage in the intake manifold 6c of the intake manifold 6. And the flange 6d at the upstream end of the intake manifold 6 is fixed to the valve housing 21, so that the downstream end is connected to the intake manifold 6 supported by the engine 1.
And the upstream end are connected to the valve housing 21.

Therefore, on the upstream side of the intake manifold 6,
That is, the portion that protrudes from the engine 1 and to which the throttle valve is attached can be firmly supported by the EGR valve device 11, so that a stay exclusively supporting the portion where the throttle valve is to be attached is unnecessary.

In the above-described embodiment, the communication part 28c of the cooling water passage 28 is formed so that the EGR control valve mounting part is covered from three sides.
Can be formed so as to cover the cylinder head 3 side and the lower side of the EGR control valve mounting portion.

[0058]

As described above, according to the present invention, E
Since the heat of the valve housing of the GR valve device is transmitted by conduction to the cooling water flowing through the cooling water passage, the exhaust gas flowing through the EGR control valve attached to the valve housing and the exhaust gas passage of the valve housing can be cooled by the cooling water. it can. Further, since the exhaust gas passage and the cooling water passage intersect at the EGR control valve mounting portion, the EG
Cooling water can be flowed near the R control valve.
The GR control valve can be efficiently cooled.

Therefore, the EGR control valve can be cooled, and the exhaust gas is cooled, so that the charging efficiency of the intake air can be relatively increased. Further, the exhaust gas passage and the cooling water passage are formed in one valve housing. And compact EGR valve device for a direct injection engine.

According to the second aspect of the present invention, the exhaust gas passage is opened and closed by the reciprocating valve body.
The upstream and downstream sides of the exhaust gas passage from the EGR control valve (one end and the other end of the valve housing)
It is formed so as to be deviated to one and the other in the opening and closing direction of the valve element.
Since the upstream side and the downstream side of the cooling water passage are formed so as to overlap in the opening and closing direction of the valve body with respect to the upstream side and the downstream side of the exhaust gas passage, the valve is provided with respect to the upstream side and the downstream side of the exhaust gas passage. The cooling water passage can be formed by using a dead space formed in one and the other of the opening and closing directions of the body.

Therefore, the cooling water passage can be formed while minimizing the space occupied by the valve housing.

According to the third aspect of the present invention, since the valve seat of the EGR control valve does not need to be provided in the valve housing, a valve seat support portion is not required inside the valve housing. For this reason, since there is no restriction caused by providing the valve seat support portion, that is, there is no restriction that the valve body support portion is firmly formed or that the position of the valve seat does not change due to thermal expansion. The degree of freedom in designing the exhaust gas passage and the cooling water passage in the valve housing is increased, and both passages can be formed in ideal shapes.

Therefore, the wall formed in the valve housing is formed thin so as to reduce the thermal resistance, and the EGR is formed.
A structure capable of cooling the control valve and the exhaust gas more efficiently can be adopted, and the two passages can be formed compactly.

Further, in the EGR valve device according to the present invention, the shape of the other portion of the valve housing can be freely changed as long as the shape and dimensions of the portion where the EGR control valve is mounted in the valve housing match. .
That is, even if a plurality of types of valve housings are formed in accordance with the model of the engine, only one type of EGR control valve may be used. For this reason, a plurality of types of EGR valve devices
It can be formed while sharing the control valve, and the cost can be reduced.

According to the present invention, the engine side of the EGR control valve is cooled by conducting heat from the valve housing to the engine, and the side opposite to the engine is formed so as to surround the engine side. It is cooled by the cooling water flowing through the cooling water passage.

For this reason, since the EGR control valve can be cooled from the surroundings, the EGR control valve can be efficiently cooled. Further, since the cooling water directly flows from the engine into the valve housing without passing through the piping, a piping for guiding the cooling water to the cooling water passage in the valve housing is unnecessary. From this point as well, downsizing can be achieved.

According to the fifth aspect of the invention, since the downstream end portion is connected to the valve housing in the middle of the intake manifold supported by the engine and the upstream end portion, the throttle in the intake manifold protrudes from the engine. The portion where the valve is mounted can be firmly supported by the EGR valve device.

For this reason, since a stay exclusively supporting a portion where the throttle valve is mounted is not required, the intake system can be made compact using the EGR valve device.

[Brief description of the drawings]

FIG. 1 is a front view of a direct injection engine equipped with an EGR valve device according to the present invention.

FIG. 2 is a side view showing a state where the engine is viewed from an intake manifold side.

FIG. 3 is a plan view of the engine.

FIG. 4 is an enlarged front view showing an EGR valve device mounting portion.

FIG. 5 is an exploded perspective view showing a cylinder head and an EGR valve device.

FIG. 6 is a sectional view taken along line VI-VI of the EGR valve device in FIG. 4;

FIG. 7 is a sectional view taken along line VII-VII in FIG.

FIG. 8 is a diagram showing a state in which the EGR valve device is viewed from a downstream side.

9 is a sectional view taken along line IX-IX in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine, 3 ... Cylinder head, 6 ... Intake manifold, 11 ... EGR valve device, 21 ... Valve housing,
22: EGR control valve, 22a: valve body, 22b ...
Valve drive device, 22c ... valve seat, 22d ... case, 27
... exhaust gas passage, 27a ... upstream part, 27b ... downstream part, 28
... cooling water passage, 28a ... upstream part, 28b ... downstream part, 28
c: communication part, 33: exhaust gas outlet pipe.

Claims (5)

[Claims] 1. An EGR control valve, comprising: a valve housing provided with the EGR control valve;
An exhaust gas passage and a cooling water passage extend from one end of the valve housing to the other end of the valve housing, and the exhaust gas passage and the cooling water passage intersect in the vicinity of the EGR control valve mounting portion of the valve housing. EGR for a direct injection engine
Valve device. 2. The E for a direct injection type engine according to claim 1.
In the GR valve device, the EGR control valve has a structure in which the valve body reciprocates, and the exhaust gas passage and the cooling water passage overlap at one end side and the other end side of the valve housing in the opening and closing direction of the valve body. An EGR valve device for an in-cylinder injection type engine, wherein the position of the valve body in the opening and closing direction is opposite between the side and the other end. 3. The EGR valve device for a cylinder injection type engine according to claim 1, wherein the EGR control valve is assembled by assembling a valve body, a valve seat, and a valve body driving device into one case. An EGR valve device for a direct injection type engine, wherein the EGR control valve is configured as a three-dimensional body and the EGR control valve is mounted on a valve housing. 4. The EGR valve device for a direct injection type engine according to claim 1, wherein the valve housing is fixed to an outer wall of the engine, and an upstream end of the cooling water passage is provided with a valve. The housing is opened to the mating surface on the engine side of the housing and connected to the cooling water outlet of the engine. The portion of the cooling water passage corresponding to the EGR control valve includes the side of the EGR control valve opposite to the engine. An EGR valve device for a direct injection type engine, wherein the EGR valve device is formed so as to surround the EGR control valve from at least three sides. 5. The E for a direct injection type engine according to claim 4, wherein
In the GR valve device, a downstream side of the exhaust gas passage is connected to an intake passage in the middle of the intake manifold via a metal pipe, and an upstream end of the intake manifold is fixed to a valve housing. EGR valve device for internal injection type engine.